/* Callgraph based analysis of static variables.
- Copyright (C) 2004, 2005 Free Software Foundation, Inc.
+ Copyright (C) 2004, 2005, 2007 Free Software Foundation, Inc.
Contributed by Kenneth Zadeck <zadeck@naturalbridge.com>
This file is part of GCC.
GCC is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
-Software Foundation; either version 2, or (at your option) any later
+Software Foundation; either version 3, or (at your option) any later
version.
GCC is distributed in the hope that it will be useful, but WITHOUT ANY
for more details.
You should have received a copy of the GNU General Public License
-along with GCC; see the file COPYING. If not, write to the Free
-Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
-02110-1301, USA. */
+along with GCC; see the file COPYING3. If not see
+<http://www.gnu.org/licenses/>. */
/* This file mark functions as being either const (TREE_READONLY) or
- pure (DECL_IS_PURE).
+ pure (DECL_PURE_P). It can also set the a variant of these that
+ are allowed to infinite loop (DECL_LOOPING_CONST_PURE_P).
This must be run after inlining decisions have been made since
otherwise, the local sets will not contain information that is
struct funct_state_d
{
enum pure_const_state_e pure_const_state;
+ bool looping;
bool state_set_in_source;
};
if (lookup_attribute ("used", DECL_ATTRIBUTES (t)))
{
local->pure_const_state = IPA_NEITHER;
+ local->looping = false;
return;
}
if (TREE_THIS_VOLATILE (t))
{
local->pure_const_state = IPA_NEITHER;
+ local->looping = false;
return;
}
are CHECKING_WRITE, this cannot be a pure or constant
function. */
if (checking_write)
- local->pure_const_state = IPA_NEITHER;
+ {
+ local->pure_const_state = IPA_NEITHER;
+ local->looping = false;
+ return;
+ }
if (DECL_EXTERNAL (t) || TREE_PUBLIC (t))
{
if (TREE_THIS_VOLATILE (t))
{
local->pure_const_state = IPA_NEITHER;
+ local->looping = false;
return;
}
if (checking_write)
{
local->pure_const_state = IPA_NEITHER;
+ local->looping = false;
return;
}
else if (local->pure_const_state == IPA_CONST)
/* When bad things happen to bad functions, they cannot be const
or pure. */
if (setjmp_call_p (callee_t))
- local->pure_const_state = IPA_NEITHER;
+ {
+ local->pure_const_state = IPA_NEITHER;
+ local->looping = false;
+ }
if (DECL_BUILT_IN_CLASS (callee_t) == BUILT_IN_NORMAL)
switch (DECL_FUNCTION_CODE (callee_t))
case BUILT_IN_LONGJMP:
case BUILT_IN_NONLOCAL_GOTO:
local->pure_const_state = IPA_NEITHER;
+ local->looping = false;
break;
default:
break;
case LABEL_EXPR:
if (DECL_NONLOCAL (TREE_OPERAND (t, 0)))
/* Target of long jump. */
- local->pure_const_state = IPA_NEITHER;
+ {
+ local->pure_const_state = IPA_NEITHER;
+ local->looping = false;
+ }
break;
case CALL_EXPR:
l->pure_const_state = IPA_CONST;
l->state_set_in_source = false;
+ if (DECL_LOOPING_CONST_OR_PURE_P (decl))
+ l->looping = true;
+ else
+ l->looping = false;
/* If this function does not return normally or does not bind local,
do not touch this unless it has been marked as const or pure by the
l->pure_const_state = IPA_CONST;
l->state_set_in_source = true;
}
- if (DECL_IS_PURE (decl))
+ if (DECL_PURE_P (decl))
{
l->pure_const_state = IPA_PURE;
l->state_set_in_source = true;
for (i = 0; i < order_pos; i++ )
{
enum pure_const_state_e pure_const_state = IPA_CONST;
+ bool looping = false;
+ int count = 0;
node = order[i];
/* Find the worst state for any node in the cycle. */
if (pure_const_state < w_l->pure_const_state)
pure_const_state = w_l->pure_const_state;
+ if (w_l->looping)
+ looping = true;
+
if (pure_const_state == IPA_NEITHER)
break;
if (!w_l->state_set_in_source)
{
struct cgraph_edge *e;
+ count++;
+
+ if (count > 1)
+ looping = true;
+
for (e = w->callees; e; e = e->next_callee)
{
struct cgraph_node *y = e->callee;
/* Only look at the master nodes and skip external nodes. */
y = cgraph_master_clone (y);
+
+ if (w == y)
+ looping = true;
if (y)
{
funct_state y_l = get_function_state (y);
pure_const_state = y_l->pure_const_state;
if (pure_const_state == IPA_NEITHER)
break;
+ if (y_l->looping)
+ looping = true;
}
}
}
{
case IPA_CONST:
TREE_READONLY (w->decl) = 1;
+ DECL_LOOPING_CONST_OR_PURE_P (w->decl) = looping;
if (dump_file)
- fprintf (dump_file, "Function found to be const: %s\n",
+ fprintf (dump_file, "Function found to be %sconst: %s\n",
+ looping ? "looping " : "",
lang_hooks.decl_printable_name(w->decl, 2));
break;
case IPA_PURE:
- DECL_IS_PURE (w->decl) = 1;
+ DECL_PURE_P (w->decl) = 1;
+ DECL_LOOPING_CONST_OR_PURE_P (w->decl) = looping;
if (dump_file)
- fprintf (dump_file, "Function found to be pure: %s\n",
+ fprintf (dump_file, "Function found to be %spure: %s\n",
+ looping ? "looping " : "",
lang_hooks.decl_printable_name(w->decl, 2));
break;
&& !(errorcount || sorrycount));
}
-struct tree_opt_pass pass_ipa_pure_const =
+struct simple_ipa_opt_pass pass_ipa_pure_const =
{
+ {
+ SIMPLE_IPA_PASS,
"pure-const", /* name */
gate_pure_const, /* gate */
static_execute, /* execute */
0, /* properties_provided */
0, /* properties_destroyed */
0, /* todo_flags_start */
- 0, /* todo_flags_finish */
- 0 /* letter */
+ 0 /* todo_flags_finish */
+ }
};
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